Association of Vascular Endothelial Growth Factor Gene Polymorphisms with Susceptibility and Clinicopathologic Characteristics of Colorectal Cancer

Since vascular endothelial growth factor (VEGF) is known to be a potent pro-angiogenic factor, we evaluated the potential association of two VEGF gene polymorphisms (-634G>C and 936C>T) with the susceptibility and the clinicopathologic characteristics of colorectal cancer (CRC). The VEGF genotypes were determined using fresh colorectal tissue from 465 patients who had undergone a surgical resection and peripheral blood lymphocytes from 413 healthy controls by PCR/DHPLC assay. For the -634G>C polymorphism, the -634 GC or CC genotype was associated with a decreased risk of CRC (odds ratio [OR], 0.62; p=0.001) as a dominant model of C allele, whereas the 936 TT genotype correlated with advanced stage/ metastasis, a high serum level of CA19-9, and an higher grade in patients with CRC. In the haplotype analyses, haplotype -634C/936C and -634G/936T were associated with a decreased susceptibility of CRC (OR, 0.53 and 0.56; p<0.001, respectively). These observations imply that the VEGF gene polymorphisms may be associated with the susceptibility or clinicopathologic features of CRC. However, further studies of other VEGF sequence variants and their biological functions are needed to understand the role of the VEGF gene polymorphisms in the development and progression of CRC

Identification of a novel merozoite surface antigen of Plasmodium vivax, PvMSA180

Background: Although a number of Plasmodium vivax proteins have been identified, few have been investigated as potential vaccine candidates. This study characterized the Plasmodium vivax merozoite surface antigen 180 (PvMSA180, PVX_094920), a novel P. vivax antigenic protein. Methods: The target gene was amplified as four overlapping domains (D1, D2, D3 and D4) to enable expression of the recombinant protein using cell-free and bacterial expression systems. The recombinant PvMSA180 proteins were used in protein microarrays to evaluate the humoral immune response of 72 vivax-infected patients and 24 vivax-naive individuals. Antibodies produced in mice against the PvMSA180-D1 and -D4 domains were used to assess the subcellular localization of schizont-stage parasites with immunofluorescence assays. A total of 51 pvmsa180 sequences from 12 countries (41 sequences from PlasmoDB and 6 generated in this study) were used to determine the genetic diversity and genealogical relationships with DNAsp and NETWORK software packages, respectively. Results: PvMSA180 consists of 1603 amino acids with a predicted molecular mass of 182 kDa, and has a signal peptide at the amino-terminus. A total of 70.8% of patients (51/72) showed a specific antibody response to at least one of the PvMSA180 domains, and 20.8% (15/72) exhibited a robust antibody response to at least three of the domains. These findings suggest that PvMSA180 is targeted by the humoral immune response during natural infection with P. vivax. Immunofluorescence analysis demonstrated that PvMSA180 is localized on the merozoite surface of schizontstage parasites, and pvmsa180 sequences originating from various geographic regions worldwide showed low genetic diversity. Twenty-two haplotypes were found, and haplotype 6 (Hap_6, 77%) of pvmsa180 was detected in isolates from six countries. Conclusions: A novel P. vivax surface protein, PvMSA180, was characterized in this study. Most of P. vivax-infected patients had specific antibodies against particular antigenic domains, indicating that this protein is immunogenic in naturally exposed populations. Genetic analysis of worldwide isolates showed that pvmsa180 is less polymorphic than other well-known candidates and that some haplotypes are common to several countries. However, additional studies with a larger sample size are necessary to evaluate the antibody responses in geographically separated populations, and to identify the function of PvMSA180 during parasite invasion.Publisher PDFPeer reviewe

Inhibition of parasite invasion by monoclonal antibody against epidermal growth factor-like domain of Plasmodium vivax merozoite surface protein 1 paralog

The Plasmodium vivax merozoite surface protein 1 paralog (PvMSP1P), which has epidermal growth factor (EGF)-like domains, was identified as a novel erythrocyte adhesive molecule. This EGF-like domain (PvMSP1P-19) elicited high level of acquired immune response in patients. Antibodies against PvMSP1P significantly reduced erythrocyte adhesion activity to its unknown receptor. To determine PvMSP1P-19-specific antibody function and B-cell epitopes in vivax patients, five monoclonal antibodies (mAbs) and 18-mer peptides were generated. The mAb functions were determined by erythrocyte-binding inhibition assay and invasion inhibition assay with P. knowlesi. B-cell epitopes of PvMSP1P-19 domains were evaluated by peptide microarray. The pvmsp1p-19 sequences showed limited polymorphism in P. vivax worldwide isolates. The 1BH9-A10 showed erythrocyte binding inhibitory by interaction with the N-terminus of PvMSP1P-19, while this mAb failed to recognize PkMSP1P-19 suggesting the species-specific for P. vivax. Other mAbs showed cross-reactivity with PkMSP1P-19. Among them, the 2AF4-A2 and 2AF4-A6 mAb significantly reduced parasite invasion through C-terminal recognition. The linear B-cell epitope in naturally exposed P. vivax patient was identified at three linear epitopes. In this study, PvMSP1P-19 N-terminal-specific 1BH9-A10 and C-terminal-specific 2AF4 mAbs showed functional activity for epitope recognition suggesting that PvMSP1P may be useful for vaccine development strategy for specific single epitope to prevent P. vivax invasion.Publisher PDFPeer reviewe

SARS-CoV-2 Omicron variant causes brain infection with lymphoid depletion in a mouse COVID-19 model

Background The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. Results K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. Conclusion Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model

Changes in Hepatic Gene Expression upon Oral Administration of Taurine-Conjugated Ursodeoxycholic Acid in ob/ob Mice

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent and associated with considerable morbidities. Unfortunately, there is no currently available drug established to treat NAFLD. It was recently reported that intraperitoneal administration of taurine-conjugated ursodeoxycholic acid (TUDCA) improved hepatic steatosis in ob/ob mice. We hereby examined the effect of oral TUDCA treatment on hepatic steatosis and associated changes in hepatic gene expression in ob/ob mice. We administered TUDCA to ob/ob mice at a dose of 500 mg/kg twice a day by gastric gavage for 3 weeks. Body weight, glucose homeostasis, endoplasmic reticulum (ER) stress, and hepatic gene expression were examined in comparison with control ob/ob mice and normal littermate C57BL/6J mice. Compared to the control ob/ob mice, TUDCA treated ob/ob mice revealed markedly reduced liver fat stained by oil red O (44.2±5.8% vs. 21.1±10.4%, P<0.05), whereas there was no difference in body weight, oral glucose tolerance, insulin sensitivity, and ER stress. Microarray analysis of hepatic gene expression demonstrated that oral TUDCA treatment mainly decreased the expression of genes involved in de novo lipogenesis among the components of lipid homeostasis. At pathway levels, oral TUDCA altered the genes regulating amino acid, carbohydrate, and drug metabolism in addition to lipid metabolism. In summary, oral TUDCA treatment decreased hepatic steatosis in ob/ob mice by cooperative regulation of multiple metabolic pathways, particularly by reducing the expression of genes known to regulate de novo lipogenesis

Laboratory information management system for COVID-19 non-clinical efficacy trial data

Background : As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results : In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions : This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.This research was supported by the National research foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2020M3A9I2109027 and 2021M3H9A1030260)

Characterization of growth and thermal behaviors of thin films for the advanced gate stack grown by chemical vapor deposition

textAbstract – Studies have been done on the materials for alternative gate dielectrics (high-k) and a metal gate electrode, which will replace conventional SiO2 gate dielectric and poly silicon gate electrode, for the sub100 nm CMOS technologies. Ultrathin HfO2 films prepared by chemical vapor deposition on Si(100) were annealed in high vacuum or N2 ambient at high temperature and their thermal stability was measured. Based on in-situ XPS, annealing HfO2 films grown by CVD on clean Si(100) leads to silicide formation at 950 o C for ultrahigh vacuum but not 4 Torr of N2. For an HfO2 film capped with amorphous Si, silicide does form upon annealing in 4 torr, but not 760 torr, of N2. TEM shows when hafnium silicide forms, it forms discontinuous islands. HfON thin film prepared by chemical vapor deposition on silicon substrate showed superior thermal stability compared to HfO2 thin film. X-ray photoelectron spectroscopy studies shows that HfON thin film is chemically stable in contact with silicon up to 1000 o C under high vacuum. Excellent resistance to crystallization of HfON thin film during high temperature process is proven by a glancing angle XRD. MOS devices using HfON dielectric thin film showed better electrical properties than HfO2. CVD TaN film exhibited excellent thermal stability in terms of chemical, structural, and electrical aspects. PMOS compatible work function (~5.0 eV) and the excellent electrical performance of CVD TaN gate electrode suggest that it is a promising candidate to replace p+ poly silicon for sub-100 nm CMOS technology.Materials Science and Engineerin